An intervertebral disk prosthesis system as described in the outset is known from US 2007/0191958 A1 for example. The advantage of intervertebral disk prosthesis systems of this type is that they can be implanted into a patient's body via a posterior point of entry. In contrast to intervertebral disk prostheses comprising just a single prosthesis component which, in accord with current standard practice, are implanted via an anterior point of entry, large vessels do not need to be mobilized in order to reach the intervertebral disk space in the case of a posterior point of entry. In consequence, damage to the vessels can be prevented and any subsequently necessary revision of the intervertebral disk prosthesis system is thereby simplified. Furthermore, the use of a posterior point of entry has the advantage that the decompression of the spinal cord or the nerve roots that is frequently required can be effected simultaneously in the course of the surgical treatment. Moreover, any existing facet arthrosis can also be treated dorsally at the same time.
One problem encountered when implanting intervertebral disk prosthesis systems of the type described hereinabove via a posterior point of entry is the correct placement of the prosthesis components. A further challenge is presented by the distraction of the intervertebral disk compartment that is necessary during this, this also being referred to as the intervertebral disk space. Access thereto is only possible by retraction of the dura mater or the nerve root. A direct view into the intervertebral disk space is not possible so that resection of the intervertebral disk and placement of the prosthesis components must be effected along curved paths and this has to be done quasi “blindly” by the operating surgeon. Should two prosthesis components be inserted independently of one another into the intervertebral disk space, these then not being connected directly to one another but only being connected indirectly via the vertebral bodies that border onto the intervertebral disk space, then it is important that the prosthesis components be positioned relative to each other in a precise pre-defined manner. This is especially necessary in order to achieve as large a physiological degree of movement as possible, the so-called “Range of Motion” (ROM), for the intervertebral disk prosthesis system as well.
It is therefore desirable to provide an intervertebral disk prosthesis system that a substantially natural range of motion of the intervertebral disk prosthesis system is attainable as independently as possible of the positioning of the two prosthesis components relative to each other and to the neighboring vertebral bodies.